The invention relates generally to the field of systems and methods for estimating ego-motion (that is, xe2x80x9cself-motion) of a moving vehicle, and more specifically to systems and methods that estimate ego-motion using successively-recorded images recorded along the vehicle""s path of motion.
Accurate estimation of the ego- (xe2x80x9cself-xe2x80x9d) motion of a vehicle relative to a roadway is an important component in autonomous driving and computer vision-based driving assistance. Using computer vision techniques to provide assistance while driving, instead of mechanical sensors, allows for the use of the information that is recorded for use in estimating vehicle movement to also be used in detecting obstacles, identifying lanes and the like, without the need for calibration between sensors as would be necessary with mechanical sensors. This reduces cost and maintenance.
There are several problems in estimating ego-motion of a vehicle. Typically, roads have few feature points, if any. The most obvious features in a road, such as lane markings, have a generally linear structure, whereas background image structures, such as those associated with other vehicles, buildings, trees, and the like, will typically have many feature points. This will make image- or optical-flow-based estimation difficult in practice. In addition, typically images that are recorded for ego-motion estimation will contain a large amount of xe2x80x9coutlierxe2x80x9d information that is either not useful in estimating ego-motion, or that may result in poor estimation. For example, in estimating of ego-motion relative to a fixed structure such as a road, images of objects that are moving relative to the road, such as other moving vehicles and even moving wipers, will contribute false information for the ego-motion estimation. In addition, conditions that degrade image quality, such as raindrops and glare, will also make accurate ego-motion estimation difficult.
The invention provides a new and improved system and method for estimating ego-motion using successively-recorded images recorded along the vehicle""s path of motion.
In brief summary, the invention provides an ego-motion determination system for generating an estimate as to the ego-motion of a vehicle moving along a roadway. The ego-motion determination system includes an image information receiver and a processor. The image information receiver is configured to receive image information relating to a series of at least two images recorded as the vehicle moves along a roadway. The processor is configured to process the image information received by the image receiver to generate an ego-motion estimate of the vehicle, including the translation of the vehicle in the forward direction and the rotation of the vehicle around a vertical axis as between, for example, successive images.
Several methodologies are disclosed for generating the ego-motion estimate of the vehicle.